Rear portion of a battery



FIG. 1 is a front view of a rear portion of a battery showing my new design;

FIG. 2 is a right side elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a bottom plan view thereof; and,

FIG. 5 is a top plan view thereof.

The broken line showings throughout the views are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a rear portion of a battery, as shown and described. 